| We study rare processes of the standard model of particle physics (SM) in events with missing transverse energy ( / ET ), no leptons, and two or three jets, of which at least one is identified as originating from a b-quark ( / ET +b-jets signature). We present a search for the SM Higgs boson produced in association with a W or Z boson when the Higgs decays into bb¯. We consider the scenario where Z → nunu, or W → lnu and the lepton escapes detection. This dissertation analyzes 7.8 fb--1 of data collected by the CDF II experiment at Fermilab.;For the first time, we analyze events with relaxed kinematic requirements, yielding an increase of 30-40% in acceptance to the WH/ZH signal. We collect events from three different triggers and parametrize the efficiency of their logical combination (OR) using a novel artificial neural network (NN) technique. To increase the sensitivity to the signal, we implement a NN to remove the huge instrumental background. An additional NN is used to discriminate the Higgs signal from the remaining background.;We check our background modeling by comparing data against backgrounds in many control regions, and find good agreement. Observing no significant excess in the data, we place 95% confidence level (C.L.) upper limits on the Higgs boson production cross section. For a mass of 115 GeV/c 2 the expected (observed) limit is 2.9 (2.3) times the standard model prediction. Compared to the last iteration of this analysis, this result improves the significance by 10% throughout the 100--150 GeV/c 2 mass range. This is one of the most sensitive at the Tevatron in this mass range.;We cross-check the tools developed in this dissertation by measuring the cross-section of top pair, electroweak single top and diboson ( WZ + ZZ) production. |
